WO2011076890A1

WO2011076890A1 - Method for creating metal reinforcement for a turbine engine blade

Info

Publication number: WO2011076890A1
Application number: PCT/EP2010/070576
Authority: WO
Inventors: Thierry Jean Emile Flesch; Jean-François FROMENTIN; Stéphane André Leveque; Laetitia Sanchez
Original assignee: Snecma
Priority date: 2009-12-23
Filing date: 2010-12-22
Publication date: 2011-06-30
Also published as: CA2785374C; BR112012015720A2; RU2012130953A; US20120255176A1; US9199345B2; JP2013527359A; BR112012015720B1; CN102686356B; EP2516107A1; CN102686356A; FR2954200B1; RU2551741C2; JP5628342B2; FR2954200A1; EP2516107B1; CA2785374A1

Abstract

The present invention relates to a method for creating a metal reinforcement (30) for a leading or trailing edge of a turbine engine blade (10) comprising a reinforcement foot (32) and head (34). Said method consecutively comprises: a step of creating a plurality of V-shaped tapered elements (30a, 30b, 30c, 30d) that form different parts of said metal reinforcement (30) so that said metal reinforcement (30) is divided into a plurality of parts distributed between said foot (32) and said head (34); a step of positioning said parts on equipment that is shaped like said leading or trailing edge of said turbine engine blade; and a step of rigidly connecting the different parts so as to form said complete profile of said one-piece metal reinforcement (30) by recombining the different parts.

Description

PROCESS FOR MAKING A METAL REINFORCEMENT

TURBOMACHINE DAWN.

The present invention relates to a method for producing a metallic blade reinforcement composite or metal turbomachine.

More particularly, the invention relates to a method for producing a turbomachine blade leading edge metal reinforcement.

The field of the invention is that of turbomachines and more particularly that of the fan blades, made of composite or metallic material, of a turbomachine and whose leading edge comprises a metallic structural reinforcement.

However, the invention is also applicable to the production of a metal reinforcement intended to reinforce a turbomachine blade trailing edge.

It is recalled that the leading edge corresponds to the front part of an airfoil which faces the airflow and which divides the airflow into an intrados airflow and a flow of air. extrados air. The trailing edge corresponds to the posterior part of an aerodynamic profile where the intrados and extrados flows meet.

It is known to equip the fan blades of a turbomachine, made of composite materials, with a metallic structural reinforcement extending over the entire height of the blade and beyond their leading edge as mentioned in FIG. EP1908919. Such a reinforcement makes it possible to protect the composite blading during an impact of a foreign body on the blower, such as, for example, a bird, hail or pebbles.

In particular, the metal structural reinforcement protects the leading edge of the composite blade by avoiding risks of delamination, fiber breakage or damage by fiber / matrix decohesion.

Conventionally, a turbomachine blade has a surface aerodynamic device extending in a first direction between a leading edge and a trailing edge and, in a second direction substantially perpendicular to the first direction, between a foot and an apex of the blade. The metallic structural reinforcement follows the shape of the leading edge of the aerodynamic surface of the blade and extends in the first direction beyond the leading edge of the aerodynamic surface of the blade to match the profile of the blade. the intrados and the upper surface of the dawn and in the second direction between the foot and the top of the dawn.

In known manner, the metallic structural reinforcement is a metal part made entirely by milling from a block of material.

However, the metal reinforcement of a blade leading edge is a complex piece to achieve, requiring many rework operations and complex tools involving significant realization costs.

In this context, the invention aims to solve the problems mentioned above by proposing a method for producing a leading edge metal reinforcement or turbomachine blade trailing edge to significantly reduce the costs of production. of such a piece and to simplify the manufacturing range.

To this end, the invention proposes a method for producing a leading edge, or trailing edge, turbomachine blade reinforcement comprising a reinforcing foot and a reinforcing head, said method comprising successively:

a step of producing a plurality of V-shaped tapered elements forming different sectors of said metal reinforcement, such that said metal reinforcement is divided into several sectors distributed between said foot and said head;

a step of positioning said sectors on a tooling taking the form of said leading edge or said trailing edge of said turbomachine dawn;

a step of securing the various sectors so as to form said complete profile of said monoblock metal reinforcement by recombination of the different sectors.

Thanks to the invention, the metallic structural reinforcement is made simply and quickly from a plurality of sectors which are then secured to form a complete monoblock reinforcement.

The realization of the metal reinforcement by the recombination of several sectors made independently avoids the drifts related to the one-piece manufacture of such a part, and especially at the thin side of the reinforcement which tend to twist.

In fact, the step of producing several sectors of the reinforcement makes it possible to limit the stresses stored in the part during the manufacturing process and thus the deformation of the thin-walled flanks during removal of the piece from the tooling.

This production method thus makes it possible to overcome the complex implementation of the reinforcement by milling in the mass from one-piece flats requiring large volume of processing material and consequently significant costs in supply of raw material.

The method according to the invention also makes it possible to substantially reduce the manufacturing costs of such a part.

The method for producing a turbomachine blade metal reinforcement according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:

during said step of producing a plurality of elements forming said sectors of said metal reinforcement, each sector is produced by means of a laser melting process; said step of joining the different sectors is carried out by means of a soldering diffusion method;

the method comprises a hot conformation step carried out simultaneously with said step of joining;

- The method comprises a step of demolding said metal reinforcement of said tool, said tool being formed by a plurality of removable sections, said demolding being operated by the successive removal of said removable sections;

the method comprises a step of finishing said metal reinforcement consisting of a sub-step of polishing the surface of said reinforcement and / or a substep of recovery of the flanks of said reinforcement;

said step of joining the various sectors is carried out by means of a welding method; in this case, advantageously, said step of joining the various sectors is successively followed by:

a step of positioning said secured sectors forming said reinforcement on a tooling taking the form of said leading edge or said trailing edge of said turbomachine blade;

a thermal stress relaxation relaxation step; a hot conformation step;

a demolding step of said metal reinforcement of said tooling, said tooling being formed by a plurality of removable sections distributed between said base and said head of said reinforcement;

- A finishing step of said metal reinforcement consisting of a sub-step of polishing the surface of said reinforcement and / or a substep of recovery of the sidewalls of said reinforcement.

The invention also relates to a method of repairing a turbomachine blade having a used metal reinforcement of the leading edge or the trailing edge of said blade, said method comprising: a step of separating said used metal reinforcement from said blade;

a step of producing a metal reinforcement of the leading edge or turbomachine blade trailing edge according to the invention,

- A step of securing said metal reinforcement made in the previous step on said turbomachine blade.

The invention also relates to a tool for implementing the method of producing a turbomachine blade metal reinforcement according to the invention comprising a plurality of removable sections.

The tool according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:

said tool comprises a number of removable sections greater than the number of sectors of the reinforcement;

said tooling is made of a material having a coefficient of expansion greater than the coefficient of expansion of the material of said reinforcement.

Other features and advantages of the invention will emerge more clearly from the description which is given below, by way of indication and in no way limitative, with reference to the appended figures, among which:

FIG. 1 is a side view of a blade comprising a metallic leading edge structural reinforcement obtained by means of the embodiment method according to the invention;

- Figure 2 is a partial sectional view of Figure 1 along a cutting plane AA;

FIG. 3 is a block diagram showing the main steps for producing a turbomachine blade leading edge metallic structural reinforcement of the embodiment method according to the invention;

FIG. 4 is a view of the blade leading edge metal reinforcement turbomachine during the first step of the process illustrated in FIG. 3;

FIG. 5 is a view of the turbomachine blade leading edge metal reinforcement during the second step of the process illustrated in FIG. 3;

FIG. 6 is a view of the turbomachine blade leading edge metal reinforcement in its final state obtained by the embodiment method according to the invention illustrated in FIG. 3.

In all the figures, the common elements bear the same reference numbers unless otherwise specified.

FIG. 1 is a side view of a blade comprising a metallic leading edge structural reinforcement obtained by means of the embodiment method according to the invention.

The blade 10 illustrated is for example a mobile blade of a fan of a turbomachine (not shown).

The blade 10 has an aerodynamic surface 12 extending in a first axial direction 14 between a leading edge 16 and a trailing edge 18 and in a second radial direction 20 substantially perpendicular to the first direction 14 between a foot 22 and a summit 24.

The aerodynamic surface 12 forms the extrados face 13 and intrados 1 1 of the blade 10, the extrados face 13 of the blade 10 being shown in FIG. The intrados 11 and the extrados 13 form the lateral faces of the blade 10 which connect the leading edge 16 to the trailing edge 18 of the blade 10.

In this embodiment, the blade 10 is a composite blade typically obtained by draping a woven composite material. By way of example, the composite material used may be composed of an assembly of woven carbon fibers and a resinous matrix, the assembly being formed by molding using a vacuum resin injection method of RTM (for "Resin Transfer Molding"). The blade 10 has a metal structural reinforcement 30 bonded at its leading edge 16 and which extends both in the first direction 14 beyond the leading edge 16 of the aerodynamic surface 12 of the blade. dawn 10 and in the second direction 20 between the foot 22 and the apex 24 of the dawn.

As represented in FIG. 2, the structural reinforcement 30 matches the shape of the leading edge 16 of the aerodynamic surface 12 of the blade 10 that it extends to form a leading edge 31, said leading edge of the reinforcement .

Conventionally, the structural reinforcement 30 is a one-piece piece having a substantially V-shaped section having a base 39 forming the leading edge 31 and extended by two lateral flanks 35 and 37 respectively fitting the intrados 11 and extrados 13 the aerodynamic surface 12 of the dawn. Flanks 35, 37 have a tapered or thinned profile towards the trailing edge of the blade.

The base 39 has a rounded internal profile 33 capable of conforming to the rounded shape of the leading edge 16 of the blade 10.

The structural reinforcement 30 is metallic and preferably based on titanium. This material has indeed a high energy absorption capacity due to shocks. The reinforcement is glued on the blade 10 by means of adhesive known to those skilled in the art, such as a cyanoacrylic or epoxy glue.

This type of metal structural reinforcement 30 used for the turbomachine composite blade reinforcement is more particularly described in particular in the patent application EP1908919.

The method according to the invention makes it possible to carry out a structural reinforcement as illustrated in FIGS. 1, 2 and 6, FIGS. 2 and 6 illustrating the reinforcement 30 in its final state.

FIG. 3 represents a block diagram illustrating the main steps of a method for producing a metallic structural reinforcement blade leading edge 10 as illustrated in FIGS. 1 and 2.

The first step 1 10 of the embodiment method 100 is a step of producing several sectors 30a, 30b, 30c, 30d of the metal reinforcement 30.

FIG. 4 particularly illustrates the different sectors 30a, 30b, 30c, 30d obtained during the first step 1 10.

For this purpose, the metal reinforcement 30 is previously divided into several sectors during the design or during the construction of a digital model.

According to an advantageous embodiment of the invention, the different sectors of the reinforcement 30 are made independently by a rapid prototyping method, and more particularly by means of a laser melting process. Indeed, the laser melting is a process which makes it possible to produce each sector of the reinforcement 30 by the deposition of several successive layers of material, which makes it possible to easily create complex shapes and in particular the tapered V shape of the metal reinforcement 30 with low thicknesses at the flanks 35, 37.

The laser melting process or laser melting sintering method is a method known to those skilled in the art and treated in many patents, such as in particular patents EP2060343 or EP2125339; therefore we will not describe in more detail the operating principle of this manufacturing process.

The realization of the metal reinforcement 30 by the recombination of several sectors 30a, 30b, 30c, 30d avoids the drifts related to the manufacture of such a piece in one piece from a flat part, and in particular to twisting flanks 35, 37 of small thickness.

Each sector 30a, 30b, 30c, 30d, made in the first step 1 10, forms part of the base 39, the leading edge 31 and the sidewalls 35, 37 of the final reinforcement 30.

The second step 120 of the production method 100 is a step of positioning the different sectors 30a, 30b, 30c, 30d on a specific form tooling 40 for the purpose of recombination. This second positioning step 120 is illustrated in FIG.

The tooling 40 is formed by the combination of several sections 40a, 40b, 40c, 40d, 40e, 40f which cooperate together so as to form a recess 43 complementary to the internal profile 33 of the reinforcement 30. The impression 43 of the tool 40 substantially corresponding to the profile of the blade 10 when the different sections 40b, 40c, 40d, 40e, 40f are assembled.

Thus during this second step, the different sectors 30a, 30b, 30c, 30d of the reinforcement 30 are positioned sector by sector on the tool 40 so as to completely build the profile of the reinforcement on the tooling. The shape of the tooling 40, and in particular the profile of the impression 43 are made so as to form the contour and the desired intrados and extrados profile of the metal reinforcement 30.

Advantageously, the tool 40 comprises a number of sections greater than the number of sectors of the reinforcement 30.

The third step 130 of the production method 100 is a step of assembling, or securing, the different sectors 30a, 30b, 30c, 30d of the reinforcement 30 by a diffusion brazing process. To do this, the joints 31 present between each sector 30a, 30b, 30c, 30d attached are filled by solder cords obtained by soldering diffusion from a filler metal in the form of strip or in the form of powder. This filler metal secures the various sectors 30a, 30b, 30c, 30d to form a monobloc reinforcement 30 with its final profile.

It is recalled that soldering diffusion is an operation consisting in completely migrating the filler metal into the base material until the disappearance of the molten metal portion.

In particular, diffusion brazing makes it possible to obtain excellent results for assembling relatively small machined workpieces and profiles. complex.

The fourth step 140 of the method of embodiment 100 is a hot shaping step performed in the same form tool 40 as in the previous steps, the tool being then placed in a furnace heated to the forging temperature of the material used.

This hot conformation step makes it possible to shape the reinforcement 30 in order to obtain its final shape.

Preferably, the tool 40 is made of a material having a coefficient of expansion greater than the coefficient of expansion of the reinforcement material. For example, the tool 40 may be made of steel when the reinforcement is made of titanium. The profile of the tool 40 and the dimensions of the tool 40 are designed taking into account the removal of the different materials used.

According to a preferred embodiment of the invention, the hot forming step 140 is carried out during the soldering step 130.

The fifth step 150 is a demolding step of said reinforcement 30 of the tooling 40. For this purpose, the different sections 40a, 40b, 40c, 40d, 40e, 40f of the tooling 40 are removable and able to disassemble individually from each other. in order to facilitate demolding of the reinforcement 30.

In order to facilitate demolding, it is possible to initially prepare the tooling 40 by depositing a protective layer on the impression 43 of the tooling 40 so as to prevent the reinforcement 30 from sticking to the tooling 40. for example, this protective layer may be an alumina layer.

Finally, the sixth step 160 of the production method 100 is a finishing step and recovery of the reinforcement 30 by machining. This finishing step 160 consists notably of:

at the resumption of flanks 35, 37; this step consisting in particular of the trimming of the flanks 35, 37 and the thinning of the intrados and extrados flanks 35, 37; - Polishing the reinforcement 30 to obtain the required surface condition.

FIG. 6 illustrates the reinforcement 30 in its final state obtained by the embodiment method according to the invention.

In association with these main production steps, the method according to the invention may also comprise non-destructive testing steps of the reinforcement 30 making it possible to ensure the geometrical and metallurgical conformity of the assembly obtained. By way of example, the non-destructive tests can be carried out by an X-ray method.

According to a second embodiment of the invention, the step of assembling or joining the different reinforcements by diffusion brazing is replaced by a step of assembling the various reinforcements by welding, for example by means of a beam electron.

In this second embodiment, the welding assembly step is performed without the use of form tooling. This step comes after the step of realization of different sectors of the reinforcement.

Thus, in this second embodiment, the method of making a blade blade leading edge metal structural reinforcement 10 as illustrated in FIGS. 1 and 2 comprises:

a first step of producing several sectors 30a, 30b, 30c, 30d of the metal reinforcement, for example by a laser melting method;

a second welding assembly step of the different sectors 30a, 30b, 30c, 30d constituting the different parts of the reinforcement;

a third step of positioning said sectors 30a, 30b, 30c, 30d secured together on a tool forming the internal imprint of the reinforcement and comprising the profile of the leading edge of the turbomachine blade; a fourth heat stress relaxation treatment step;

a fifth heat conformation step;

- A sixth demolding step of the metal reinforcement 30 of the tool, the tool being divided into different removable sections so as to facilitate demolding the reinforcement 30;

a step of finishing the metal reinforcement 30 consisting of a sub-step of polishing the surface of the reinforcement and / or a sub-step of taking up the sides of the reinforcement 30.

The process according to the invention has been described mainly for a titanium-based metal structural reinforcement; however, the process according to the invention is also applicable with nickel-based or steel-based materials.

The invention has been particularly described for producing a metal reinforcement of a composite turbomachine blade; however, the invention is also applicable for producing a metal reinforcement of a turbomachine metal blade.

The invention has been particularly described for producing a metal reinforcement of a turbomachine blade leading edge; however, the invention is also applicable for producing a metal reinforcement of a trailing edge of a turbomachine blade.

The invention has been particularly described with a laser melting method for carrying out the first step; however, the first step may be performed for example by another prototyping method or a machining method.

The advantage of the laser melting of the reinforcement by a plurality of independent sectors makes it possible to limit the stresses stored in the part during the laser melting process and thus the deformation of the thin-walled flanks when the part is removed. tooling. Indeed, the reinforcement has thin-walled flanks that tend to deform when removing the workpiece from the tooling plus the size of the workpiece is important.

The method of producing a metal reinforcement according to the invention fits perfectly into a global process for repairing a composite or metallic turbine engine blade. The method of repairing a turbomachine blade then consists of:

- A first step of separating the used metal reinforcement by pyrolysis means for heating the adhesive or the resin to a temperature of about 100 to 400 ° C to soften and / or deteriorate the adhesive used to secure the reinforcement metallic on the turbomachine dawn;

a second step of producing a new metal reinforcement according to the invention;

- And finally a third step of securing the metal reinforcement made in the previous step, by gluing with an adhesive known to those skilled in the art to paste a reinforcement on a blade, such as a cyanoacrylic glue or still an epoxy glue.

Other advantages of the invention include the following:

- reduction of implementation costs;

- reduction of the production time;

- simplification of the manufacturing range;

- reduction of material costs.

Claims

1. Method for producing a metal reinforcement (30) for a leading edge or turbine blade vane (10) having a foot (32) and a reinforcing head (34), said method comprising successively:

a step (100) for producing a plurality of V-shaped tapered elements (30a, 30b, 30c, 30d) forming different sectors of said metal reinforcement (30), so that said metal reinforcement (30) is divided in several sectors distributed between said foot (32) and said head (34);

a positioning step (120) of said sectors (30a, 30b, 30c, 30d) on a tool (40) taking the form of said leading edge or said trailing edge of said turbine engine blade (10);

- A step (130) of securing the different sectors so as to form said complete profile of said monobloc metal reinforcement (30) by recombination of the different sectors (30a, 30b, 30c, 30d).

2. A method of producing a turbomachine blade metal reinforcement (30) according to claim 1 characterized in that during said step (100) of producing a plurality of elements forming said sectors (30a, 30b, 30c, 30d) of said metal reinforcement (30), each sector (30a, 30b, 30c, 30d) is realized by means of a laser melting process.

3. A method of producing a metal reinforcement (30) turbomachine blade according to one of claims 1 to 2 characterized in that said step (120) of securing the different sectors (30a, 30b, 30c, 30d) is carried out by means of a diffusion brazing method.

A method of producing a metal reinforcement (30) turbomachine blade according to claim 3 characterized in that it comprises a step (140) of hot conformation carried out simultaneously with said step of joining (130).

Process for producing a turbine engine blade reinforcement (30) according to one of Claims 3 to 4, characterized in that it includes a demolding stage (150) of said metal reinforcement (30) of said tool (40). said tooling (40) being formed by a plurality of removable sections (40a, 40b, 40c, 40d, 40e, 40f), said demolding being effected by the successive removal of said removable sections (40a, 40b, 40c, 40d, 40e, 40f).

A method of producing a turbine engine blade metal reinforcement (30) according to claim 5 characterized in that it comprises a step (160) of finishing said metal reinforcement (30) consisting of a polishing sub-step of the surface of said reinforcement and / or in a substep of recovery of the flanks (35, 37) of said reinforcement (30).

Process for producing a turbine engine blade metal reinforcement (30) according to one of Claims 1 to 2, characterized in that the said step (1 10) for securing the different sectors (30a, 30b, 30c, 30d) is performed by means of a welding process.

8. A method of producing a turbomachine blade metal reinforcement (30) according to claim 7 characterized in that said step (1 10) of securing the different sectors (30a, 30b, 30c, 30d) is successively followed by:

a step of positioning said joined sectors (30a, 30b, 30c, 30d) forming said reinforcement on a tooling taking the form of said leading edge (31) or said trailing edge of said turbine engine blade (10);

a thermal stress relaxation relaxation step;

a hot conformation step;

- A demolding step of said metal reinforcement (30) of said tool, said tool being formed by a plurality of removable sections distributed between said foot (32) and said head (34) of said reinforcement;

- A finishing step of said metal reinforcement (30) consisting of a sub-step of polishing the surface of said reinforcement (30) and / or in a substep of recovery flanks (35, 37) of said reinforcement (30).

A method of repairing a turbomachine blade having a used metal reinforcement of the leading edge or the trailing edge of said blade, said method comprising:

a step of separating said used metal reinforcement from said blade;

- A step of producing a metal reinforcement (30) of the leading edge or turbine blade vanishing edge (10) according to one of claims 1 to 8,

- A step of securing said metal reinforcement (30) made in the previous step on said blade (10) of a turbomachine.

10. Tooling (40) for implementing the method of producing a Turbomachine blade metal reinforcement (30) according to one of claims 1 to 9, characterized in that said tooling (60) is formed by a plurality of removable sections (40a, 40b, 40c, 40d, 40e, 40f).

1 1. Tool (40) according to claim 10 characterized in that it comprises a number of removable sections (40a, 40b, 40c, 40d, 40e, 40f) greater than the number of sectors (30a, 30b, 30c, 30d) of the reinforcement ( 30).

12. Tooling (40) according to one of claims 10 to 1 1 characterized in that said tool (60) is made of a material having a coefficient of expansion greater than the coefficient of expansion of the material of said reinforcement (30).